JWSS - Journal of Water and Soil Science

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Transporting borrow materials for proper infrastructure of water channels to bear the load of such structures is important in the development plans. Therefore, in this research clay nanocomposite material with a weight ratio of %1 was added to the soil. Soil sample was taken from the bed of the C25 canal (distributary of GanjAfrooz diversion dam within Alborz project area) at various intervals and the depth of 1 meter. Unconfined compression strength and consolidation tests were performed on the selected soil. The results showed that the addition of nanoclay to the soil increased the rate of shear resistance, cohesion property and compressibility of soil, respectively, equal to 14.13, 14.13and 82.76 percent. Also, angle of failure and ultimate void ratio decreased. As a result, the addition of nanoclay to the soil makes soil strength and stability greater and there are no problems caused by bed erosion and transporting of borrow material for infrastructure of channel.

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To deal with the destructive effects of swelling soils, different methods have been proposed by researchers. Chemical stabilization of expansive soils is one of the effective methods that are low-cost and efficient economically and technically. Recently, with the improvements of nano science in nanomaterials production and application, using this type of materials has been considered in different sciences especially geotechnical engineering. In this research, the effect of adding different amounts of nanoclay on swelling behavior modification of two types of clayey soils with low plasticity and high plasticity has been studied. For this purpose, first, identification tests were implemented on two types of clayey soils and nanoclay. Then, swelling potential tests were conducted on samples of soils with different amounts of nanoclay including (0, 0.25, 0.5, 1 and 2 weight percent) considering curing ages of 3 and 10 days. The results showed that the effect of adding nanoclay to the high plastic soils swelling potential is more than adding it to that of low plastic soils. So, adding 0.25 to 0.5 weight percent of nanoclay reduces the swelling potential of high plastic soils about 67 percent, and that of low plastic solis about 3 percent. Furtheremore, the maximum reduction in swelling potential increases by adding up to 0.5 percent nanoclay; and decreases for adding amounts more than 0.5 percent.